fn main() {
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).ok();
	let n: Vec<i64> = s.split_whitespace().flat_map(str::parse).collect();
	let mut ans: Vec<i64> = vec![];
	if n[1] >= n[2] && n[2] % n[0] == 0 {
		ans.push(n[2] / n[0]);
	}
	if (n[2] + n[1]) % n[0] == 0 {
		ans.push((n[2] + n[1]) / n[0]);
	}
	match ans.len() {
		0 => println!("-1"),
		_ => ans.iter().for_each(|i| println!("{}", i)),
	}
}